The invention relates to a device for connecting a valve housing to an actuator in a process valve acting as a lift valve, with the valve housing consisting of at least a valve housing part, with at least a first and a second connector, which are connected to the valve housing part and which establish a connection to the internal space, with a connection opening arranged in the valve housing between the connectors, in or on which at least a seating surface is formed, with at least a translatably slidable closure part, which cooperates (cooperate) with the attributed seating surface and controls (control) the connection opening, with an actuating rod fastened on each closure part, which leads out in a sealing manner through a housing opening of the valve housing facing the connection opening and which is connected with an actuating piston of an actuator, with a lantern-type housing connecting the valve housing to the actuator, the lantern-type housing having at least at its valve housing-sided end a means for the connection with the valve housing.
The lift valve of the type designated above has the necessary characteristics of a stop valve, in which at least a component of the translative opening and closing movement of its closure part (single seat valve) formed as a seat disk or its closure parts (double-seat valve) formed as seat disks is/are oriented vertically to the attributed seating surface. The lift valve can also be realized in the framework of the mentioned embodiments as a gate valve, in which the closure part formed as sliding piston and/or the closure parts formed as sliding pistons rides or ride during the translative opening and closing movement along an attributed cylindrical seating surface. In the double seat valve a combination of seat disk and sliding piston is also known.
A closure part seal arranged in the seat disk acts together axially or axially/radially with the attributed seating surface, while a closure part seal arranged in the sliding piston acts together radially with the attributed cylindrical seating surface. The translative opening and closing movement of the respective closure part is generated via a pressure means actuated piston drive, preferably a pneumatic actuated one, wherein the return movement of an actuating piston takes place generally through a spring, preferably a coil spring. The piston drive can work, based on the closure piece and the attributed seating surface, spring closing or spring opening. For the reduction of the opening forces of the stop valve the actuating rod of the closure part can be constructed in the area of its penetration through the valve housing in the form of a so-called pressure equalization piston, so that the compressive forces acting in the lift direction on the closure part undergo a part or full compensation from the fluid (e.g. product) available in the valve housing at the projected end face of the pressure equalization piston.
There are many different embodiments of process valves of the type described above, wherein, for the purpose of a safe separation of a fluid situated in the valve housing from the pressure means acting upon the actuating piston in the actuator, a so-called lantern-type housing is arranged between the valve housing and the actuator. The opening movement of the process valves takes place, in relation to the vertical normal position of valve, either upwards or downwards, so that one speaks of a valve opening upwards or downwards. As a smallest possible overall height to the bottom is generally desired, the actuator is arranged as a rule above the valve housing.
A decisive selection criterion for process valves of the type discussed is not only its height to the bottom, but also that to the top. The latter is essentially determined by the design of the lantern-type housing and of the actuator, wherein it is already known for a reduction in height, to integrate the springs of the actuator of a double seat valve completely in the available space of the lantern-type housing (state of the art e.g. according to EP 0 646 741 B1). In another well-known process valve, which has a singular closure part, the lantern-type housing remains completely free from built-in components saving height in this regard (DE 20006 594 U1). Comparable conditions are known in a double seat valve according to DE 38 35 944 A1.
In the above mentioned double seat valves, the actuating rods of the closure members, especially when the latter are realized as sliding pistons, are designed as a rule in the form of the above mentioned pressure equalizing piston. In order to ensure sufficient compensation of the forces on the respective closure member through corresponding counteracting forces on the attributed pressure equalizing piston, these pressure equalizing pistons are extended in the cross-section mostly approximately to the effective projected cross-section of the attributed closure member. The big passing through cross-sections through the valve housing resulting therefrom on the one hand complicates the sealing of these pressure equalization pistons, on the other hand however the pressure equalizing piston provides space in its interior for a reception saving height of the springs of the valve actuator.
The type of the connection between valve housing and actuator via the lantern-type housing also exerts an influence on the height of the respective process valve, wherein this influence is actually fairly small. More decisive in this connection is the influence of this connection on the assembly- and disassembly costs as well as the costs to realize this connection. For decades essentially the following shortly outlined three forms of this connection have been realized in this regard.
On the one hand it is a connection by means of flanges which are screwed together. The publications EP 0 646 741 B1 and EP 0 174 384 B1 show respectively a connection in this regard between valve housing and lantern-type housing in a double seat valve. This connection is time-consuming in the assembly or disassembly and a twist between valve housing and actuator is only possible in the framework of the circular pitch of the connecting screws.
In the majority of all process valves of the type discussed, the so-called clamping flange connection is currently also preferred, which for example is disclosed in DE 200 06 534 U1 (process valve with a singular closure member) or in DE 38 35 944 A1 or EP 0 834 689 A1 (in each case a double seat valve). Hereby the housing parts to be connected with one another have a so-called clamping flange, which is conically inclined on its outside flank, radially outwards. The respective couple of clamping flanges, that symmetrically taper radially outwards, is held together by a divided clamping ring winding round almost 360 degrees, complementary to the inclined flanks, wherein both halves of the clamping ring are connected and held together either via a hinge on the one hand and on the other hand a screw joint or via two screw joints. A connection in this respect is easy to assemble and disassemble and makes possible a positioning of the actuator opposite the valve housing in any position. The costs for this type of connection are however higher than in the case of a screwed flange connection.
Finally it is known to carry out the connection between valve housing and actuator housing via a screw connection (e.g. so-called screwed pipe connection according to DIN 11851 or DIN 11864) (WO 2007/128360 A1). In this case, the lantern-type housing carries as a rule the groove nut and the bolt thread is integrally molded in the valve housing. This connection is preferentially used in sterile procedural processes, because the grove nut features outwardly less impact surface for contamination than a screwed flange or clamping flange connection. The costs are the highest in comparison to both the aforementioned connection types; there are no disadvantages in contrast to the aforementioned type.
The publication DE 90 13 788 U1 describes a connection piece for an accessory device for the heat and water supply, in particular for a water meter, a heat meter or a filter top part, with a stop valve that is mounted in a rotatable manner in a housing between a through position and a stop position, and with a top piece for the accessory device which can be connected in a detachable manner to the housing. Hereby the top piece is connected with the housing by means of a bayonet lock in which a bolt is guided in an L-shaped nut. The top piece is linked in such a way with the stop valve (this means concretely a traction connection in the peripheral direction, not a clamping connection in the axial direction), that in the mounting of the top piece on the housing the stop valve is opened and is closed during disassembly. For the frictional connection by force of the top piece and of the stop valve, it is preferred if a coupling member (bore hole) is connected with the top piece, the coupling member being detachably connectable with the counter coupling member (bolt) of the valve. In the positioning of the top piece the coupling member is thereby connected in frictional manner to the counter coupling member (bolt engages in hole) and the movement of the top piece (in the circumferential direction) is thereby transferred to the valve, which is correspondingly opened or closed.
In WO 2007/128 360 A1 housing aggregations for monitoring, controlling and regulating systems for a process valve are described. The respective housing aggregation consists of a sequence of individual housing adaptors, which are connected with one another via a bayonet-lock similar joint mechanism.
It is the aim of the present invention to design a device for connecting a valve housing to an actuator in a process valve of the type mentioned above that acts as a lift valve, which has a smaller construction height and is less expensive than all known devices of this type, and which is furthermore of very simple design with the greatest possible opening safety.